Switching the constant current source consisting of the application circuit W723

As shown in FIG Multiport W723 is being integrated adjustable constant current regulator composition application switching regulator circuit, the output current of 1A. Illustra

ted circuit, W723 reference base voltage (approximately 7.2V) through R1, R2 dividing the voltage of approximately 3V added to the non-inverting input, and also via a resistor R3, R4 partial pressure after adding to the inverting input, R4 and another low-end shunt resistor R5 connected. When the inverting and non-inverting input of approximately balanced, the shunt voltage drop across the resistor R5 is about 1V. R6 is used to adjust the output ripple current. When the current feedback circuit increases, the regulator output stage unit is turned on, W723 Uin end a current pulse of 12mA, the driving transistor VT. Zener diode VD1 regulator unit used to bias the output stage, and the diode VD2 is used to eliminate the reverse spikes. Capacitor C1 and inductor L filter composed to smoothly switch the output waveform. The size of the maximum operating frequency depends on the load, typically 20kHz.